On October 2rd, in a security notice Canonical published details about some Python 2.7 vulnerabilities affecting its Ubuntu 11.10 and Ubuntu 11.04 operating systems.
According to Canonical, several security issues were fixed in Python 2.7. It was discovered that urllib and urllib2 modules would process location headers that specify a redirection to file: URLs.
A remote attacker could exploit this to obtain sensitive information or cause a denial of service. Several other exploits in the Python 2.7 package have also been repaired.
The security flaws can be fixed if you upgrade your system(s) to the latest python2.7 and python2.7-minimal, specific to each operating system. To apply the update, run the Update Manager application.
In general, a standard system update will make all the necessary changes. A system restart won't be necessary to implement the changes.